Plant Nutrient Elements

Classification of Plant Nutrient Element 

1.    Major or Macro Nutrient Elements 

2.    Micronutrient Elements 

1. Major or Macro Nutrient Elements 

The elements which are required for plant nutrition in large amount are known as major nutrient elements. The number of major plant nutrient elements is 9. These are- 

1. Carbon 2. Hydrogen 3. Oxygen  4 Nitrogen 5. Phosphorus 6. Potassium 7. Calcium 8. Magnesium 9. Sulphur 

2. Micronutrient Elements 

The elements, which are required for plant nutrition only in trace amount, are known as micronutrient elements. The number of micronutrient elements is 8. These are

1. Iron 2. Manganese 3. Molybdenum 4. Copper 5. Zinc 6. Boron 7. Cobalt  8. Chlorine 

Though required in only small quantity, the micronutrients are essential for plant growth and development

Sources of Plant Nutrients 

The main source of plant nutrients is two. these are_ 

1. Natural sources 2. Artificial sources

Soil, air and water are the main 3 natural sources of plant nutrients. The artificial sources of plant nutrients are the organic manure and chemical fertilizer.

Natural Sources

A. Soil 

Excluding carbon, hydrogen and oxygen the rest of the 14 plant nutrient elements are absorbed by plants from soil. 

B. Air

 Plant mostly absorb carbon and oxygen from the air.

C. Water

 Plant absorb hydrogen and oxygen from water. Besides, plant can absorb other mineral elements which are found to stay in water in soluble form.  

Artificial Sources

A. Organic Manure

 Most the nutrients required for plant nutrition are found in organic manure. Cowdung, compost, organic wastes, straw and weeds after decomposition may be used as organic manure. 

B. Chemical Fertilizer

 Urea, Triple Super Phosphate, Muriate of potash etc. are the examples of chemical fertilizers. A chemical fertilizer normally supplies the major plant nutrient elements such as nitrogen, phosphorus and potassium.

Functions of Nutrient Elements

 The nutrient elements are known to perform many functions to complete the life cycle of a plant. Some of the nutrients directly help in growth of plant, some help in preventive diseases. While some other help in maturity and ripening of seed. Some nutrients also help in absorption of other nutrient elements. The combined influence of the above mentioned functions determine the quality and quantity of yield, in addition to the beneficial effects, some of the elements also exerts detrimental role when present in excess amounts. Plant nutrients when applied in balanced form show beneficial effects. Otherwise, application in excess or deficient amount show negative results. Some important functions of plant nutrient elements are described here. 

Nitrogen

 The influence of nitrogen in fulfilling the life cycle and optimum growth of plant is most important. Urea fertilizer is used to supply nitrogen to crop plants in Bangladesh. The nitrogen content of urea is about 46 percent. 

Functions of Nitrogen in plant

 1. Gives a deep green colour to the plant. 

 2. Helps in photosynthesis, metabolism and respiration of plants

 3. Results in rapid growth of leaf and stem.

 4. Improves the quality of areal grain crops, fodder and leafy  vegetables.

 5. Helps in production of tiller in cereal grain crops.

Phosphorus

 The most important phosphatic fertilizers are triple super phosphate and diammonium phosphate. Triple Super Phosphate contains about 45 percent phosphate (P205) 

Functions of Phosphorus in Plants

 1. Participates in the division of plant cells.

 2. Accelerates the growth of plants.

 3. Forms the root system of plant.

 4. Helps in flowering of plant in right time and ripening of fruits. 
 5. Improves the quality of crop products.

 6. Supply energy and strengthens plant structure.

Potassium

 Muriate of potash is most important among the potassium fertilizers. Muriate of photash contains   about 60 percent potash. 

Function of Potassium in Plants

 1. Increases the disease resitance power of plants.

 2. Helps in cell division in plants.

 3. Helps in carbohydrate production in plant leaves.

 4. Controls, movement of carbohydrate and other biochemical compounds within the  plant.

 5. Keep balance in the uptake of nitrogen and phosphorus in  plants. 

Sulphur

 Gypsum or calcium sulphate is the most important sulphur fertilizer. Gypsum contains about 14 percent sulphur.

Functions of Sulphur in Plants

 1. Increases the yield of oil seed crops 

 2. Helps in increasing the nodulation in roots of the leguminous crop plants.

Zinc 

Zinc sulphate is one of the most popular zinc fertilizers. Zinc sulphate contains up to 36 percent zinc and 17 percent sulphur 

Functions of Zinc in Plants

 1. Helps in protein formation and plant growth.

 2. Helps in flower and fruit production of plants. 

Calcium

 Gypsum or calcium sulphate may be applied for calcium supplement in crop fields. Calcium sulphate contains about 22 percent calcium. 

Functions of Calcium in Plants.

  1. Strengthens walls of the plant cells.

  2. Helps in growth and development of plant roots.

  3. Make the plant cells strong and elastic.

  4. Increases the yield of pulse crops. 

Iron 

Ferrous sulphate is most important among the iron fertilizer. This ferrous sulphate fertilizer may be applied both in the soil and in the plant as spray. 

Functions of Iron in Plant 

1. Forms the green chlorophyll of plant leaves 

2. Helps in absorption of nitrogen by plant 

3. Acts as catalyst for activating different enzymes

Nutrient Deficiency Symptoms

Pants when grown in soil having deficiency in plant nutrient elements show definite symptoms in their leaves, stems and in their formation and sizes. Some important nutrients deficiency symptoms are briefly described below 

Symptoms due to Nitrogen Deficiency in Plants

 1. At first the leaves become light green in colour 

 2. In case of progressive deficiency the leaves become gradually yellow.

 3. Normal growth of the plant is stunted.

 4. Tillering is reduced in cereal grain crops.

 5. Yield is drastically reduced

 6. The seeds are found to be immature 

 7. Leaf-drop occurs in fruit plants.

 8. The buds and twigs gradually die. 

Symptoms of Phosphorus Deficiency Plants

 1. The normal growth and development of shoot and root of plants are seriously affected by                      phosphorus deficiency.

 2. Cell division is hampered in absence of phosphorus.

 3. Lack of phosphorus causes delayed growth of plants.

 4. Phosphorus deficiency reduces the number and size of leaves.

 5. The protein content of plant is reduced in absence of sufficient  phosphorus.

 6. Flowering is greatly by affected by phosphorus deficiency.

 7. Phosphorus deficiency results in dropping of fruit and the size of fruit become small. 

Symptoms of Potassium Deficiency Plants

 1.  The resistance power of plant is reduced ill absence of  sufficient potassium.

 2.  Potassium deficiency increases pest infestation in crop plants.
 3. Lack of potassium reduces the rate of photosynthesis.

 4. Growth is stunted in potassium deficiency plants.

 5. Potassium deficiency is responsible for bronze colouration of  leaves.

 6. Growth of plant root is stunted in case of potassium  insufficiency.

 7. Drought resistance power of crop plant is decreased by potassium deficiency. 

Symptoms of Sulphur Deficiency in Plants

 1. Cell division is seriously hampered in absence of sulphur. 

 2.  Plants get dwarf structure when deficient in sulphur.

 3. Size of leaves becomes small and found to be discoloured.

 4.  Plant maturity is delayed due to sulphur insufficiency.

 5.  The stems and branches of plants become narrow when sulphur is a limiting factor

 6. The yield of oil seed crops are greatly reduced when grown in sulphur deficient soil. 

Symptoms of Zinc Deficiency in Plants

 1.  Whitish spots appear at the base of rice leaves when zinc deficiency becomes prominent.

 2. The interveinal spaces of maize and cotton leaves are discoloured if zinc deficiency occurs.

 3.  Growth of leaf is stunted

 4.  The older leaves of rice plant found to show a rust colour if  zinc deficiency is severe.

 5. Curling of lemon leaf is common system of zine deficiency. 

Symptoms of Calcium Deficiency in Plants 

 1.  The apex of young it laves show abnormal formation when  plants suffer from  calcium  deficiency.

 2. The symptoms of chlorosis occur in leaf when calcium supply in  plant is inadequate.

 3.  The midrib and the leaf margins are found to show yellow and brown shades when calcium nutrition is limiting.

 4. The plant leaves get smaller size in case of calcium deficiency.  
 5. Plants a dwarf structure due to the lack of calcium.

Symptoms of Iron Deficiency in Plants

1. At first chlorosis occurs in the young leaf due to iron deficiency.
 2. The interveinal spaces show chlorotic symptoms when iron is  lacking. This chlorosis then spread gradually over the whole leaf.

3. The leaves become brownish when the deficiency of iron in plant is severe.